Check Front Fog Light System

Trouble symptom: 

Headlight illuminates, but front fog light does not illuminate.

1. CHECK FRONT FOG LIGHT SYSTEM. 
   1. Turn the ignition switch to ON.
   2. Turn the lighting switch to the switch 2 (HEAD) position.
   3. Turn the dimmer & passing switch to OFF (neutral position).
   4. Turn the front fog light switch of the lighting switch to ON.

   Does the front fog light illuminate?

   Yes:  The front fog light system is normal.

   No:  Go to  2.

2. CHECK CURRENT DATA. 

   Display the [Front fog lamp SW input] data using Subaru Select Monitor. Refer to BODY CONTROL (DIAGNOSTICS)>DATA MONITOR .

   Does the display change from [OFF] ←→ [ON] when the front fog light switch of the lighting switch is operated?

   Yes:  Go to  5.

   No:  Go to  3.

3. CHECK HARNESS. 
   1. Turn the ignition switch to OFF.
   2. Disconnect the connectors of body integrated unit and combination switch (light).
   3. Check the harness between body integrated unit and combination switch (light).

      Connector & terminal 

      (i81) No. 26 - (i73) No. 4:

   Is harness normal?

   Yes:  Go to  4.

   No:  Repair or replace the harness.

4. CHECK HARNESS. 

   Check the harness between the combination switch (light) connector and the chassis ground.

   Connector & terminal 

   (i73) No. 3 - Chassis ground:

   Is the resistance less than 10 Ω?

   Yes:  Go to  5.

   No:  Repair or replace the harness.

5. CHECK FUSE AND RELAY. 
   1. Turn the ignition switch to OFF.
   2. Check M/B fuse No. 32 and front fog light relay. Refer to LIGHTING SYSTEM>RELAY AND FUSE>INSPECTION .

   Is the check result OK?

   Yes:  Go to  6.

   No:  Replace the defective fuse or relay.

6. CHECK HARNESS. 
   1. Remove the front fog light relay.
   2. Measure the voltage between relay holder and chassis ground.

      Connector & terminal 

      (B225) No. 46 (+) - Chassis ground (-):

      (B225) No. 47 (+) - Chassis ground (-):

   Is the voltage 8.5 - 16.5 V?

   Yes:  Go to  7.

   No:  Repair or replace the harness.

7. CHECK CURRENT DATA. 
   1. Turn the ignition switch to ON.
   2. Display the [Front Fog Lamp Output] data using Subaru Select Monitor. Refer to BODY CONTROL (DIAGNOSTICS)>DATA MONITOR .
   3. Turn the lighting switch to the switch 2 (HEAD) position.
   4. Turn the dimmer & passing switch to OFF (neutral position).
   5. Turn the front fog light switch of the lighting switch to ON.

   Does the display change from [OFF] ←→ [ON] when the front fog light switch of the lighting switch is operated?

   Yes:  Go to  8.

   No:  Replace the body integrated unit. Refer to SECURITY AND LOCKS>BODY INTEGRATED UNIT .

8. CHECK HARNESS. 
   1. Turn the ignition switch to OFF.
   2. Remove the front fog light relay.
   3. Disconnect the connectors of body integrated unit and front fog light.
   4. Check the harness between relay holder and body integrated unit connector.
   5. Check the harness between relay holder and front fog light connector.

      Connector & terminal 

      Body integrated unit side 

      (B225) No. 45 - (B281) No. 1:

      Front fog light side 

      (B225) No. 48 - (B488) No. 2:

      (B225) No. 48 - (B474) No. 2:

   Is harness normal?

   Yes:  Go to  9.

   No:  Repair or replace the harness.

9. CHECK HARNESS. 

   Check the harness between front fog light connector and chassis ground.

   Connector & terminal 

   (B488) No. 1 - Chassis ground

   (B474) No. 1 - Chassis ground

   Is harness normal?

   Yes:  Replace the body integrated unit. Refer to SECURITY AND LOCKS>BODY INTEGRATED UNIT .

   No:  Repair or replace the harness.